As a big Guitar Hero fan, I was pretty upset to hear that WOR would be the last in the series. I think, potentially, they could have done more.
Anyway, I'm not a massive metal fan but having looked at some of the song choices for this game I was a little intrigued and bought it.
I did enjoy the game, and what GH have done with this. They pad out a decent storyline, with excellent graphics and interesting characters. I just thought it was far too long. In the first "boss battle" if you will, you have to complete an Overture by the band Rush, which took around half an hour, maybe even more of solid playing to complete. This part of the game made absolutely no sense to me, so I was a little disappointed that they had done something so self-indulgent.
The game itself is also more technically challenging, even on the easy and beginner settings, you can feel the difference.
Although I enjoyed most of the game, it did become a little repetitive and I felt myself getting bored after a while. Some nice achievements and avatar awards to be had though.
Overall I'd give it a 3/5. There was so much more they could have explored with this game than just traditional guitar hero fare, which this essentially is, with the addition of juicy graphics.